﻿using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;

namespace WebAPI.Utils;

public class ImageHelper
{
    #region 合并用户QR图片和用户头像

    /// <summary>
    /// 合并用户QR图片和用户头像
    /// </summary>
    /// <param name="qrImg">QR图片</param>
    /// <param name="headerImg">用户头像</param>
    /// <param name="n"></param>
    /// <returns></returns>
    public Bitmap MergeQrImg(Bitmap qrImg, Bitmap headerImg, double n = 0.23)
    {
        int margin = 10;
        float dpix = qrImg.HorizontalResolution;
        float dpiy = qrImg.VerticalResolution;
        var _newWidth = (10 * qrImg.Width - 36 * margin) * 1.0f / 36;
        var _headerImg = ZoomPic(headerImg, _newWidth / headerImg.Width);
        //处理头像
        int newImgWidth = _headerImg.Width + margin;
        Bitmap headerBgImg = new Bitmap(newImgWidth, newImgWidth);
        headerBgImg.MakeTransparent();
        Graphics g = Graphics.FromImage(headerBgImg);
        g.InterpolationMode = InterpolationMode.HighQualityBicubic;
        g.SmoothingMode = SmoothingMode.HighQuality;
        g.Clear(Color.Transparent);
        Pen p = new Pen(new SolidBrush(Color.White));
        Rectangle rect = new Rectangle(0, 0, newImgWidth - 1, newImgWidth - 1);
        using (GraphicsPath path = CreateRoundedRectanglePath(rect, 1))
        {
            g.DrawPath(p, path);
            g.FillPath(new SolidBrush(Color.White), path);
        }
        //画头像
        Bitmap img1 = new Bitmap(_headerImg.Width, _headerImg.Width);
        Graphics g1 = Graphics.FromImage(img1);
        g1.InterpolationMode = InterpolationMode.HighQualityBicubic;
        g1.SmoothingMode = SmoothingMode.HighQuality;
        g1.Clear(Color.Transparent);
        Pen p1 = new Pen(new SolidBrush(Color.Gray));
        Rectangle rect1 = new Rectangle(0, 0, _headerImg.Width - 1, _headerImg.Width - 1);
        using (GraphicsPath path1 = CreateRoundedRectanglePath(rect1, 1))
        {
            g1.DrawPath(p1, path1);
            TextureBrush brush = new TextureBrush(_headerImg);
            g1.FillPath(brush, path1);
        }
        g1.Dispose();
        PointF center = new PointF((newImgWidth - _headerImg.Width) / 2, (newImgWidth - _headerImg.Height) / 2);
        g.DrawImage(img1, center.X, center.Y, _headerImg.Width, _headerImg.Height);
        g.Dispose();
        Bitmap backgroudImg = new Bitmap(qrImg.Width, qrImg.Height);
        backgroudImg.MakeTransparent();
        backgroudImg.SetResolution(dpix, dpiy);
        headerBgImg.SetResolution(dpix, dpiy);
        Graphics g2 = Graphics.FromImage(backgroudImg);
        g2.Clear(Color.Transparent);
        g2.DrawImage(qrImg, 0, 0);
        PointF center2 = new PointF((qrImg.Width - headerBgImg.Width) / 2, (qrImg.Height - headerBgImg.Height) / 2);
        g2.DrawImage(headerBgImg, center2);
        g2.Dispose();
        return backgroudImg;
    }
    #endregion

    #region 图形处理
    /// <summary>
    /// 创建圆角矩形
    /// </summary>
    /// <param name="rect">区域</param>
    /// <param name="cornerRadius">圆角角度</param>
    /// <returns></returns>
    private GraphicsPath CreateRoundedRectanglePath(Rectangle rect, int cornerRadius)
    {
        //下午重新整理下，圆角矩形
        GraphicsPath roundedRect = new GraphicsPath();
        roundedRect.AddArc(rect.X, rect.Y, cornerRadius * 2, cornerRadius * 2, 180, 90);
        roundedRect.AddLine(rect.X + cornerRadius, rect.Y, rect.Right - cornerRadius * 2, rect.Y);
        roundedRect.AddArc(rect.X + rect.Width - cornerRadius * 2, rect.Y, cornerRadius * 2, cornerRadius * 2, 270, 90);
        roundedRect.AddLine(rect.Right, rect.Y + cornerRadius * 2, rect.Right, rect.Y + rect.Height - cornerRadius * 2);
        roundedRect.AddArc(rect.X + rect.Width - cornerRadius * 2, rect.Y + rect.Height - cornerRadius * 2, cornerRadius * 2, cornerRadius * 2, 0, 90);
        roundedRect.AddLine(rect.Right - cornerRadius * 2, rect.Bottom, rect.X + cornerRadius * 2, rect.Bottom);
        roundedRect.AddArc(rect.X, rect.Bottom - cornerRadius * 2, cornerRadius * 2, cornerRadius * 2, 90, 90);
        roundedRect.AddLine(rect.X, rect.Bottom - cornerRadius * 2, rect.X, rect.Y + cornerRadius * 2);
        roundedRect.CloseFigure();
        return roundedRect;
    }
    /// <summary>
    /// 图片按比例缩放
    /// </summary>
    private Image ZoomPic(Image initImage, double n)
    {
        //缩略图宽、高计算
        double newWidth = initImage.Width;
        double newHeight = initImage.Height;
        newWidth = n * initImage.Width;
        newHeight = n * initImage.Height;
        //生成新图
        //新建一个bmp图片
        Image newImage = new Bitmap((int)newWidth, (int)newHeight);
        //新建一个画板
        Graphics newG = Graphics.FromImage(newImage);
        //设置质量
        newG.InterpolationMode = InterpolationMode.HighQualityBicubic;
        newG.SmoothingMode = SmoothingMode.HighQuality;
        //置背景色
        newG.Clear(Color.Transparent);
        //画图
        newG.DrawImage(initImage, new Rectangle(0, 0, newImage.Width, newImage.Height), new Rectangle(0, 0, initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);
        newG.Dispose();
        return newImage;
    }

    /// <summary>
    /// 创建缩略图
    /// </summary>
    /// <param name="b"></param>
    /// <param name="destHeight"></param>
    /// <param name="destWidth"></param>
    /// <returns></returns>
    public static Bitmap GetThumbnail(Bitmap b, int destHeight, int destWidth)
    {
        Image imgSource = b;
        ImageFormat thisFormat = imgSource.RawFormat;
        int sW = 0, sH = 0;
        // 按比例缩放 
        int sWidth = imgSource.Width;
        int sHeight = imgSource.Height;
        if (sHeight > destHeight || sWidth > destWidth)
        {
            if ((sWidth * destHeight) > (sHeight * destWidth))
            {
                sW = destWidth;
                sH = (destWidth * sHeight) / sWidth;
            }
            else
            {
                sH = destHeight;
                sW = (sWidth * destHeight) / sHeight;
            }
        }
        else
        {
            sW = sWidth;
            sH = sHeight;
        }
        Bitmap outBmp = new Bitmap(destWidth, destHeight);
        Graphics g = Graphics.FromImage(outBmp);
        g.Clear(Color.Transparent);
        // 设置画布的描绘质量 
        g.CompositingQuality = CompositingQuality.HighQuality;
        g.SmoothingMode = SmoothingMode.HighQuality;
        g.InterpolationMode = InterpolationMode.HighQualityBicubic;
        g.DrawImage(imgSource, new Rectangle((destWidth - sW) / 2, (destHeight - sH) / 2, sW, sH), 0, 0, imgSource.Width, imgSource.Height, GraphicsUnit.Pixel);
        g.Dispose();
        // 以下代码为保存图片时，设置压缩质量 
        EncoderParameters encoderParams = new EncoderParameters();
        long[] quality = new long[1];
        quality[0] = 100;
        EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
        encoderParams.Param[0] = encoderParam;
        imgSource.Dispose();
        return outBmp;
    }
    #endregion
}